Recently, research and development of a technology called a storage class memory (SCM) has progressed, and an SCM device to which the technology is applied appears. The SCM device represents a high-speed and high-capacity nonvolatile memory having an intermediate property between a memory, such as a dynamic random access memory (DRAM) used as a main memory of a computer, and a storage, such as a solid state drive (SSD) and a hard disk drive (HDD). If a plurality of servers can share an SCM device, there is a possibility that the SCM device can be utilized as a huger memory in comparison to a DRAM in a single server.
An operation, in which data is stored in a storage connected to a network and the data is shared between a plurality of servers, has been already in practice. In this case, if management of access authority to the data, which is shared on the storage, is not appropriately performed, unexpected data loss, leakage of secret information, and the like may simply occur. Therefore, in the related art, access authority management and the like has been performed by using a permission function on a file system, and the like.
In a case of using the SCM device as a shared memory, if not using characteristics of the SCM device, that is, high speed and refinement (byte unit) of access granularity, the intrinsic worth of the SCM device is not exhibited. Specifically, if not providing a unit that performs access in the same granularity as the granularity of a typical read/write command of a processor, e.g., a load/store command in a central processing unit (CPU) instead of performing read/write with a file IO similar to a storage with a large overhead; it is difficult to avoid an access overhead. Accordingly, it is difficult to meet expectations with a structure of the related art in which a file system is provided through network connection, and there is a demand for construction of a new structure.